Vera Keller

As historians of scientific instruments and sociologists of science alike have pointed out, metric instruments have played a powerful role in the spread and persuasiveness of science. Universal measurements allow science to be deployed across cultures, and therefore appear to offer a view from nowhere. Historians and sociologists of science have been interested in re-entangling precision instruments with their local contexts in order to trace the process through which science came to appear universal.

The thermometer presents a particularly rich case of the intersections between the local, the national, and the international in the making of a universal instrument. On the one hand, objects similar to thermometers appeared to be widely available in the early seventeenth century. On the other hand, the invention of the thermometer came to be attached to a particular set of names: Cornelis Drebbel, Robert Fludd, Galileo Galilei, and Sanctorius Sanctorii. Arguments for one inventor over the other quickly accreted nationalist overtones. Historians of invention, attempting to determine whether the world owed this crucial instrument to Italy, England, or the Netherlands, often returned time and again to the same few and partial sources.

Rather than asking ‘Who invented the thermometer?’ this paper asks ‘Where, how, and why were claims to invention made?’. Tracing the claims to Drebbel’s inventions of the thermometer reveals an international network of related Reformed artisans, philosophers, intelligencers, and merchants stretching across Central Europe, the Netherlands, England, and the New World. Objects and information travelled through this network, as did the thermometer and accounts of its origins, and they came into conflict with other networks and their claims. Pursuing such networks leads us in surprising directions towards new sources about the early thermometer, and a better understanding of its early functions and meanings.